I suspect there is a correlation between magazine size and number of rounds expended, yes. Funny, that.
There’s numerous reports over the years of multiple officers emptying magazines dozens or even hundreds of rounds fired, and nobody hit anything. At least the “bad guy” anyways.
This isn't that hard to understand for an unpracticed shooter. A cool thing to do with a laser sight on a handgun. Empty the gun for dry firing. Have someone who isn't practiced take the gun - tell them to hold the laser dot on a fixed point on the wall and dry fire 5 times as fast as they can. You will see that laser dot bounce back and forth all over the wall with a very wide radius. Especially with a revolver due to the heavier trigger pull.